“Help Grantley, Willard,” he directed, at the same time, between his clenched teeth. “Graves and I can handle this fellow, I guess.” Willard started for Nick, while Graves shifted his attack, and, edging around behind Chick, seized him by the shoulders. At the same moment he placed one knee in the small of the young detective’s back. There could be only one result. Chick was bent painfully back until his spine felt as if it was about to crack in two; then, in his efforts to relieve the strain, he lost his footing and went down, with Chester on top of him, and still clinging doggedly to his wrists. A few feet away Nick was being hard pressed by two other rascals. The pendulum of chance had swung the other way, and things looked very dubious for the detectives--and for what was left of Helga Lund! CHAPTER X. A HUMAN WHEEL. Chick had thrown himself to one side to ease the pressure on his back. Accordingly, he struck the floor on his left side. Chester and Graves dropped heavily upon him before he had more than touched the boards, the former at his feet, the latter on his shoulders. Their bony knees crushed him down, and Graves used his weight to try to pull Chick over on his back. Nick’s assistant had twisted his left wrist out of Chester’s grasp as he fell, but the renegade physician had clung for dear life to the hand which held the automatic. Chick allowed himself to be pulled over on his back--for a very good reason. His free arm had been under him as he lay on his side, and he wanted an opportunity to use it. Graves grabbed at it at once, but Chick stretched it--all but the upper arm--out of his antagonist’s reach. Graves would have to lean far over Chick in order to reach the latter’s left wrist, and, in so doing, he would expose himself not a little. Or else he would be obliged to edge around on his knees, behind Chick’s head. He chose to try the latter maneuver, but Chick feinted with his left arm. Graves dodged, and Chick’s hand darted in behind the other’s guard, grasping Graves firmly by the hair. Almost at the same instant the young detective jerked his right foot loose and gave the startled Chester a tremendous kick in the stomach. The master of the house gave a grunt and doubled up, like a jackknife. His grip on Chick’s right wrist relaxed simultaneously, and its owner tore it away. Chester had involuntarily lurched forward, and the act had brought his head well within the reach of Chick’s right hand, which was now once more at liberty. While Nick’s assistant held the struggling Graves at arm’s length by the hair, with one hand, he brought down the butt of the automatic, with all the strength he could bring to bear, on Chester’s lowered poll. He had juggled the weapon in a twinkling, so that it was clubbed when it descended. The blow was surprisingly effective, considering the circumstances. Chester groaned and toppled forward, over Chick’s legs.